Previously, many types of vehicles have been in use using the principle of a cushion of air to provide lift from the surface upon which it is operating in conjunction with thrust directed air flow for forward propulsion. In most cases, however, no consideration has been given to the control of the pitch of the vehicle to provide an optimum use of air gap or escape nozzle of the vehicle over an irregular ground surface, and also provisions to maximize the lift potential during operation over water. A search of the prior art did not disclose any patents that read directly on the claims of the instant invention. However, the following U.S. patents were considered related:
______________________________________ PATENT NO. INVENTOR ISSUE DATE ______________________________________ 3,078,939 Bollum, Sr. Feb. 26, 1963 3,187,817 Colley June 8, 1965 3,412,956 Cockerell Nov. 26, 1968 3,583,520 Kirpitznikoff June 8, 1971 3,968,851 Windt July 13, 1976 ______________________________________
Bollum, Sr. teaches an earth skimming vehicle with a rudder directly behind a screw propeller providing horizontal thrust for driving the vehicle. The rudder is provided for jaw control and is attached by a stationary vertical support on the same plane and aligned fore and aft with the vertical diameter of the propeller shroud ring. Side thrust is provided by an open cylindrical tube having a D.C. motor driven fan supplementing the rudder for steering control.
Colley discloses a power plant for ground effect aircraft and consists of one or more engines which are arranged to supply power for the operation of two separate air moving devices. A power reduction means reduces the supply whenever the speed falls below a predetermined level maintaining constant power supply to the remaining drive.
Cockerell is concerned with stabilizing a vehicle hovering over land or water. This invention provides means for bringing about a stepped pressure distribution over at least part of the cushion when the vehicle is deflected from its intended orientation with a restoring force applied righting the directional orientation.
Kirpitznikoff teaches an air cushion vehicle with the hull formed of two integral sections. The upper part forms the passenger cabin and the lower part is a plenum chamber. The sections are secured together with a flange and a bumper and side wall buoyancy chamber are included around the plenum chamber.
Windt includes a vehicle in which the lift fan and the propulsion unit are driven from the same engine in such a manner as to keep the lift fan at a constant speed and vary the propulsion fan for speed control. The lift fan is driven by two adjustable pulleys, one sensing torque from the lift fan adjusting its effective diameter, the other is regulated by spring force.